Evolutionary trade-off: having kids will break your heart

Scientists have long wondered why coronary artery disease (CAD), which develops over a lifetime, has not been eliminated through natural selection. CAD starts in young adults, progressing over time to become life-threatening. Present in human populations for millennia, it is the leading cause of death worldwide. Scientists at Yale and other medical centers have now found that genes underlying CAD also contribute to reproductive success. A genomic analysis published last summer in PLOS Genetics suggests that natural selection has relatively recently preserved genes that contribute to the risk of coronary artery disease because they also contribute to better chances of having children. This evolutionary trade-off, said contributing author Stephen C. Stearns, Ph.D., the Edward P. Bass Professor of Ecology and Evolutionary Biology, shows that “babies can break your heart.”